Advanced Materials Research Vols. 291-294

Abstract: This article mainly introduced variational problem about stress-strain relationship of unloading fractured rock mass in the excavation. In this paper, research is carried out on variational principle of unloading fractured rock mass in the stage of linear elasticity.

Abstract: Pin-cycloid driven speed reducer with three cycloid gears adopts the new driving structure of three cycloid gears at eccentric angle of 120 between each other. Three main stresses act on the cycloid gears: the stress between pin gear and cycloid wheel gear, the stress on cycloid wheel by cylinder pin of output mechanism and the stress on cycloid wheel by bearing of rotating arm. In this paper, the stress between needle gear and cycloid wheel gear is analyzed mainly by analysis.

Abstract: The relation between chlorine and combustion process of pulverized coal in tuyere zone is affected by the existence form of chorine in coal. The combustion process of pulverized coal in tuyere zone is restrained by chorine of coal when the existence form of chorine is chloride created by Cl^- and metal cation. The combustion process of pulverized coal in tuyere zone is improved by chorine of coal if chorine existents with the form of combination of HCl and nitrogen functional groups of coal macromolecules. Under the combustion conditions of tuyere zone in blast furnace, the distribution ratio of chlorine in unburned pulverized coal and blast furnace gas is approximately 60% and 40%, respectively.

Abstract: The adsorption of CH₄ onto the surfaces of perovskite-type catalysts ABO₃ ( A=La, Ba; B=Zr, Co, Ce) was investigated by a density functional theory based on the first-principles in this paper. The absorption mechanism was derived by population and electronic states analysis on the basis of the electronic and surface structure calculations. For A=Ba and B=Zr, the frontier energy state was found to the key factor in controlling the adsorption behavior of CH₄ absorbed on (001) surfaces, which is mainly contributed by oxygen and B-site ions. The most favorite adsorption site for CH₄ was located at B-sites of perovskite catalysts ABO₃, where the A-site ions adjust the charge of B-site ions and moreover affect the CH₄ adsorption.

Abstract: Back propagation (BP) neural network model was established, using the corrosion data of five kinds of recently developed bainite weathering steel and the commercial weathering steel 09CuPCrNi exposed in the offshore platform in Wanning. The influences of elements P, Cu, C and Cr on the corrosion behavior of weathering steel were studied according to the model. The experimental results indicate that the corrosion depth of bainite weathering steel corroded for 1 year could decline owing to the increasing contents of P, Cu and Cr in steel while C has little effect on the variation of the corrosion depth.

Abstract: Flame deformation correction is the main means for correcting welding deformation of thin plate, and the temperature field simulation is an important component during the flame deformation correction calculation, which will directly determine the calculation accuracy and complexity. In order to simplify the calculation, firstly, the temperature field calculation is divided into three separate processes, secondly each process id divided into heating step, heat conduction step and heat exchanging step, and mathematical models of the three processes are established through dispersing in time and space. Experiments show that this method not only can simplify the calculation, but also is with high calculation accuracy, so it is with important application value.

Abstract: According to the superiority performance, the applications of engineering plastics tend to be widely used day by day in the field of railway transport. The research of locomotive-bearing retainer is an important technology that should be resolved proposed by the Ministry of Railways’ report on the outline of the Eleventh Five-Year Plan. In this paper, the characteristics of each process of the injection molding in the different stage, the main technology parameters, and the influence of the primary process parameters on the part manufacture quality were systematically analyzed. And the modern injecting forming software and new technology were applied to analyze the injecting forming technology, to design the mould structure, to forecast the possible defects and breakdown in the process of injecting forming with the thematically design and the CAE technology. The study results can be extended to the design of other similar parts, which has very strong engineering applications significance.

Abstract: The behaviour of geologic material such as granite under impact loading is involved in the study of safety requirements of structures in extreme simulations such as earthquakes, accidental impacts or explosions. Based on incident pulse shaping design of quasi-brittle material for dynamic tests, experiments on granite under uniaxial and active confinement conditions are conducted with the split Hopkinson pressure bar(SHPB). By adding the soft material mass as the pulse shaper, the stress uniformity in the specimens before fracture is ensured and the fluctuation of test data due to incident stress pulse is avoid. The experimental results show that the compressive strength is increasing with the strain rate and the confined pressure. The fragments size decreases with the strain rate. The research method and conclusion could be used to analyze the dynamic behavior of the other brittle materials.

Abstract: This paper proposed a novel device to draw blood from the finger. PDMS is used as an actuated pump, the device has an advantage in a precise controlled the volume of blood drawn. The operation process of the blood drawing device with the deflection of the PDMS membrane is to generate negative pressure. For measuring the performance of the device, we also fabricate a PDMS tank as pig’s skin. Two different viscosity fluid are used, the red ink and pig’s blood. The result of red ink drawn is 0.2cc, and the pig’s blood is 0.1cc.

Abstract: As an outer covering of cooling aircraft engines, the air intake cover very much effects the aerodynamic performance of the aircraft under the condition of high-speed air current striking on it. In order to improve the aircraft's aerodynamic performance, the temperature field distribution of the gypsum-based Investment casting process of the air intake cover was analyzed by ANSYS software, which the Pro/E software was used as the three-dimensional modeling software. In the modeling process with Pro/E software, three default datums must be firstly established. In the same time, it is necessary to appropriately use some temporary datums. Some functions, such as Protrusion> Use Quilt> Solid or Thin,Reorder,Redefine,Reroute, are very important to generate complex curved surfaces and entities. The results of the temperature field simulation showed that the process of filling and solidification reflected the actual casting situations, forecast possible defects in casting and defective locations of the castings, order solidification was obtained which a rising head was put close to casting heat knots and final solidification positions, and ensured the feasibility and quality of the air intake cover casting.